The present invention, although useful in other applications, is especially directed to power driven striker mechanisms utilized in automotive door latches to achieve a controlled powered movement of the door to its fully closed position.
A typical standard automotive door latch assembly includes a striker which usually takes the form of a pin fixedly mounted in the door frame to project into the door opening into the path of movement of a latch member mounted on the edge of the door. In a typical arrangement, the latch member will be pivotally mounted upon the door and so arranged that as the door approaches its closed position, the latch member will engage the striker pin and further closing movement of the door will pivot the latch member into a latched engagement with the pin which positively retains the door against movement away from its closed position. Typically, at least part of the movement of the latch member into latched relationship with its striker is resisted by a spring, and to be sure that the door is fully latched, most people will habitually close the door with far greater force than necessary. This problem is especially acute in the case of sliding doors, such as those employed on vans where movement of the door during the final phase of its movement to its fully closed position must compress a resilient door seal which extends around the entire periphery of the door opening.
To overcome this problem, powered strikers are mounted on the door frame for powered movement between an outboard (with respect to the vehicle centerline) ready position at which the latch is latched to the striker and a inboard holding position in which the striker holds the latched door in its fully closed position. Examples of such arrangements are found, for example, in U.S. Pat. Nos. 4,707,007 and 4,862,640. When the door is open, the striker pin is located in its outboard ready position. Upon closure of the door, the latch on the door engages striker pin and latches the door to the striker pin while the striker pin is in its outboard position. At this time, the door may engage a limit switch on the door frame to actuate a drive motor which, through appropriate mechanism, drives the striker pin to its inboard position, the latched engagement between the door and striker pin enabling the pin to drive the door to its fully closed position. With this arrangement, only a closing force sufficient to engage the latch need to be applied, the powered movement of the striker pin providing the force necessary to compress the door seal.
The striker pin driving mechanism must be mounted in the interior of a channel shaped frame structure which defines one vertical edge of the door opening, and the space available for mounting the mechanism and access to this space is sometimes extremely restricted. A second problem encountered by such mechanisms is that of designing the mechanism in a manner such that external forces applied to the striker pin are absorbed insofar as is possible by the vehicle frame rather than by the striker pin positioning mechanism. While the closing force applied to the door need only be enough to actuate the latch, this force is frequently substantially exceeded. These impact forces and other types of shock loading applied to the vehicle door frame can, when absorbed by the mechanism, damage or backdrive the pin positioning mechanism. For proper operation of the latch, alignment of the striker with the path of movement of the door carried latch is critical. Because the resistance of the door seal to closing movement of the door increases as the door approaches it fully closed position, desirably the striker pin driving mechanism should operate at a maximum mechanical advantage as the pin approaches its inboard limit of movement.
The present invention provides a powered striker mechanism which effectively transmits external forces applied to the striker pin to the vehicle frame rather than to movable elements of the striker pin drive mechanism, applies the driving force of a rotary drive input to the striker pin with a mechanical advantage which increases as the striker pin approaches its inboard end limit, and achieves these results by a mechanism well adapted to be mounted within a restricted space. The striker pin mechanism of the present invention is also constructed in a manner which accommodates vertical and horizontal adjustment of the striker pin and its path of movement relative to the vehicle frame during installation to accurately align the pin with the path of movement of the door carried latch.